Start Control Module (SCU)
The start control module (SCU) (3/132) is in the dashboard beside the steering wheel. The Start control module (SCU) contains a module for the remote key, a motor for drawing in and ejecting the remote key and a starter button. The control module also contains 3 switches that are mounted on top of the spring where the remote key is inserted. The switches are activated on different occasions via a sledge when the remote key is inserted in the spring:
- Switch key-inserted: activates the motor for drawing in the remote key in the Start control module (SCU).
- Switch for locked remote key: informs the Central electronic module (CEM) that the remote key is in its locked position.
- Switch for ejection: activates the motor for ejecting the remote key when the remote key is pushed in after it being in its locked position. In order for the remote key to be ejected, the engine must not be running, the vehicle must not be moving (speed must be 0). Vehicles with automatic transmission must have the gear selector lever in position P.
The start control module (SCU) has an inner antenna which can be activated by a command from the central electronic module (CEM). The antenna is used to check the identity of the key when the remote control key is inserted in the module for the start control module (SCU). The antenna is activated by the central electronic module (CEM) when the remote control key is inserted in the recess of the start control module (SCU), or when the start button is pressed in (only vehicles with keyless system installed).
The start button has two switches, switch 1 and switch 2.
Switch 1 is directly connected to the central electronic module (CEM), the keyless vehicle module (KVM) and the engine control module (ECM).
The status of both the switches is checked by the start control module (SCU) and is sent to the central electronic module (CEM) via serial communication (LIN).
Both switches must close when the start button is pressed. It is enough that one switch is in the start button for the car to start. The central electronic module (CEM) compares the signals in the direct connection from switch 1 with the status signals which come from the start control module (SCU) via LIN.
If the different signals show different status in the start button a DTC can be stored in the central electronic module (CEM), and the function for autostart stops.
The remote key does not need to be inserted into the module on the Start control module (SCU) if there is a keyless vehicle module (KVM) in the vehicle. The identity of the remote key is then checked via the antennas in the passenger compartment instead. These antennas are connected to the keyless vehicle module (KVM) when the starter button is pushed.